1. Field of the Invention
The present invention relates to a manipulator including a slave arm for use under an ultimate environment such as outer space, and, more particularly, to a manipulator operating apparatus that is used to operate a manipulator.
2. Description of the Related Art
Recently, in the field of space developments, there is an idea for building such a structure as a space station in outer space and conduct various experiments there. With regard to the construction work, it is effective to realize various safe and precise works by remotely operating a working manipulator using a manipulator system.
A manipulator operating apparatus for use in such a manipulator system is equipped with a rectangular coordinate type operation unit having an operation handle that has six degrees of freedom defined by three translation shafts substantially orthogonal to one another and three rotation shafts also substantially orthogonal to one another; a manipulator is controlled in a specific command control mode to realize the desired work by remotely operating this operation unit. There are two types of command control modes: a speed command control mode for driving the manipulator interlockingly with the operation of the operation unit a a speed associated with the displacement of the operation unit, and a position command control mode under bilateral master-slave control for controlling the manipulator interlockingly with the operation of the operation unit in association with the position and state of the operation unit. In the former mode, when the operation section of the operation unit takes a reference state at a reference position, a command is given to the manipulator to make its speed to zero and the manipulator is controlled by a speed command signal corresponding to the displacement of the operation unit which is associated with the operation thereof. When an operator stops operating the operation unit and takes his (or her) hand(s) off the operation handle of the operation unit, the handle resumes the reference state and returns to the reference position. In the second mode, the operation unit is controlled at a speed corresponding to the difference between the operation force applied to the operation handle and the force applied on the manipulator by the operation of the unit, and the manipulator is controlled by a position command signal corresponding to the position and state of the operation unit. In the position command control mode, which gives the operator the feeling as if he is directly operating the manipulator, when he stops operating the operation unit and takes his hand(s) off the operation handle, this handle is kept at the operated position if no force is applied to the manipulator.
Due to the structure, however, in the speed command control mode, the above manipulator operating apparatus is suitable to a work that requires a large amount of displacement of the free end of the manipulator but is not suitable to a work requiring precision such as an alignment work.
In the position command control mode, on the other hand, this manipulator operating apparatus is suitable to the latter precision-requiring work such as an alignment work, but is not suitable to the former work that requires a large displacement of the free end of the manipulator.
In short, the convention manipulator operating apparatus has a difficulty in realizing smooth and quick works in a case in which both of the above two types of works are continuously carried out.
The speed command control mode is disclosed in Japanese Patent Disclosure No. 62-173184, and the position command control mode in a technical report given on pages 75-81 of Japanese Robot Convention Report, Vol. 6, No. 1.
The above shortcomings are common not only to a space manipulator system but also to a ground manipulator system.